In order to provide capacitors which can be mass produced at low cost, and which have accurately controlled values, it is desirable to be able to adjust the value at the end of the manufacturing operation. Capacitors have been manufactured using thin fllm technology wherein one or more electrodes are trimmed, as by use of a laser, to adjust the capacitance value. However, this thin film technology requires the formation of metal and dielectric layers by deposition in a vacuum chamber. As masks must be used in the vacuum chamber to determine the patterns of the layers, the process requires the use of sophisticated and complicated equipment, and is slow and expensive.
Capacitors have also been made by using thick film layers which can be screened so that the process is relatively simple and inexpensive. Such layers are much thicker, such as from 12 to 30 microns thick, as compared to one-third of a micron for thin film layers. Because of the thickness of the electrodes and the properties of the electrodes and dielectric materials, it has not been possible to remove a portion thereof to adjust the capacitor value, without causing damage to the capacitor. Also techniques used with thin film capacitors, such as applying a voltage across the electrodes during laser trimming to prevent shorts, does not work with thick film capacitors as the large voltage required due to the dielectric thickness may exceed the dielectric strength of the dielectric material.